It is well known to utilize PTFE and ePTFE to form vascular prostheses. It has also been known to utilize yarn or filament in wraps in combination with ePTFE grafts. For example, U.S. Pat. No. 5,607,478 to Lentz et al. shows wrapping a graft of ePTFE tubular structure with a PTFE yarn in a helical fashion to form an ePTFE graft with increased suture retention strength, radial tensile strength, crush resistance and tear propagation resistance. U.S. Pat. No. 5,556,426 to Popadiuk et al. discloses a luminal device made from a porous cylindrical PTFE tube. A fluoropolymer such as PTFE filament or coil is wrapped helically around the external surface of the tube to form a radially reinforced flexible PTFE implantable prosthesis. U.S. Pat. No. 4,955,899 to Della Corna et al. teaches compressing a portion of a porous PTFE tube along its longitudinal axis and coating of biocompatible elastomer is applied to the outer wall of the compressed portion of the PTFE tube to provide a longitudinally compliant PTFE graft which minimizes suture hole bleeding, increases suture strength and reduces serious seepage. As discussed above, although the prior art patents show ePTFE grafts with several enhanced properties, none of them show crimping an ePTFE graft.
It is, therefore, desirable to provide crimps in a vascular graft formed of a tubular ePTFE tube, which provides length adjustability as well as improves resistance to kinking, suturing properties, and other handling characteristic such as crush resistance.